Yeah, that's rough when there's a certain prevailing attitude in the class and all of the students are going along with it.
Hate to always be giving advice, but here's what I'd do:
A.) Learn all of their names- have a nametag (folded index card works well) with your name on it, and put it in front of you during class. Hand out index cards to all of the students and have them do the same. At the beginning of each class, ceremoniously bust out your nametag, and redistribute index cards to all of the students who forgot their's. People respond much better when you say "Hey, Shirley, how was your weekend?" then they do to "Hey, you with the black hair! How was your weekend?"
B.) If you really want to chat some, chat at a specified time (beginning, middle, end) of EVERY class, make EVERY student speak, and they will get into the routine.
C.) Try writing a schedule on the board at the beginning of class so they know what's coming. Mine usually looks something like this:
1.) Small Talk (Ooh, now it's not just chatting and wasting time. It has an official name and it's serious business!)
2.) Listening Comprehension - I load up a Breaking News English 2 minute news cast. I explain it's because my accent is American and it's in their best interest to get used to a British accent as well. REally, sometimes it's so I can take a rest. While the newscast is playing, I quickly scribble comprehension questions on the board, ex: "How old was the lady who punched a guy on the plane? How many months will she go to jail?" Then, after it plays, we test their comprehension by answering the questions. If they didn't get a lot of them, we play it again, and I point to a question when the answer is coming. Then we discuss the newscast. (question/comment cards are helpful here.) This will also help you get a better idea of their level/whether or not they can actually understand you.
4.) Current Events - I explain that I can't understand Chinese and when I went into the 85 degrees to get coffee this morning I saw a news report in which a man with a face mask was bowing, sobbing, and apologizing profusely to a woman in a hospital bed. Why was he doing that? What did the man do? What else is going on in Taiwan? (International reporting is really dismal here, so often I'll explain one of the big international stories, for example we discussed the slaughter in Syria during my last class.)
D.) Try going around in a circle to get them to answer questions, or do the old "Spin the pen" and whoever the cap is pointing at has to answer. This is lovely
because you can spin it, ask, then pass it to the student who answered, then they spin it and ask the next student, and low and behold, the onus to keep the discussion going is no longer on you. And, it's not your fault if the damn pen points to a shy student, it's the damn pen's fault. (I've also made a show of throwing it out the window when it pointed to someone who didn't want to talk, but that's a different story. Laughter helps ease the tension too.)
If a student doesn't answer, make a big show of going up to the board and creating some 'scaffolding' for them to answer, acting embarrassed that you, the TEACHER forgot to TEACH. Write a sentence structure they can use, and if they're really shy, just leave a couple of spaces for them to fill in adjectives. "My weekend was _______, I went to ______ with my ______. We had a ______ time." Then model it for them.
This serves a dual purpose- 1, it really is useful even for advanced students to see, word for word, how a native speaker might answer and 2, it shows the silent student "Hey, I mean business. If you sit there silently, I am going to assume your English is terrible and I'm going to teach you how to respond. This will be embarrassing so next time you'll just use the skills you have and ANSWER.
If they still don't talk, I launch into my "It's better to make a mistake in here, in this classroom, then out there, where people might laugh at you. If somebody here laughs at you, I will throw this eraser at their face and that's really going to hurt. Nobody here is allowed to laugh at you. But what if you meet a REALLY HANDSOME FOREIGNER and he wants to know how your weekend was and YOU DON'T KNOW HOW TO ANSWER and really he's the LOVE OF YOUR LIFE and you were going to have GET MARRIED AND LIVE HAPPILY EVER AFTER but now you never will..." This works equally well with old women as young college students. But the point is, this is a classroom, this is where you are allowed to make mistakes.
E.) Do some work on your own thoughts. If you think poorly of your students, it's going to come out in your mannerisms, your attitude, your facial expressions. Imagine if you were trying to speak a foreign language and the person you were talking to was looking at you like "Listening to you is such a pain in my ass." You probably wouldn't want to talk either, and they have an audience of their peers listening to this too. Even if you hide it well
they will still feel your attitude toward them. So think happy thoughts! At least you're not teaching kids